Cause they both can get mad and just punch someone or just start and hands on fist fight.
The likely answer here is spore coat.
Several types of bacteria will form a spore when they are presented with unfavorable conditions. When conditions improve, the spore germinates and the bacteria continues to replicate.
They leave no record of their existence because it's rare that fossils form. You need the right conditions in which the animal's remains are covered in silt, dirt, and rock layers in order for a fossil to form and therefore preserve the animal's remains in rocks. Otherwise, the animal's remains will be eaten by other animals or eventually rot away.
That is called uric acid and it helps them maintain internal homeostasis in hot climates by retaining water
